(9a)
CBP=128-x(sum of angle in a triangle)
CBA=180-(128-x)
sum of angle on a straight line
CBA=52+x
ADC=180-(128-x)
=52+x
Also BCD=180-x(angle on a straight line)
DCQ=180-(180-x)
DCQ=180-180+x
DCQ=x
x+52+x+76=180
2x=180-52-76
2x/2=52/2
x=26degrees